There was no West Virginia in 1856,...the current Virginia panhandle…
If the article had referred to the panhandle of Virginia, nits could have been equally picky.
There was a panhandle of Virginia which existed prior to the formation of West Virginia. I believe that is the one referenced even though it is now part of the state of West Virginia. http://en.wikipedia.org/wiki/Northern_Panhandle_of_West_Virginia
The part of the current state of Virginia which could potentially be called a panhandle doesn’t seem to be called a panhandle.
While it doesn’t matter a bit… I currently live in North Texas, which is bounded by West Texas, Central Texas, East Texas, and Oklahoma. I see these terms (and more) used with capital letters every day in print and on television without benefit of statehood.